This invention relates to metal roof restoration and more particularly to a leak prevention system which will add years to the life of a metal panel roof.
In the past, metal roofs such as standing seam roofs have been restored by the assignee of the present applicant by wire brushing the roof to remove rust and residue, testing and replacing fasteners with oversize fasteners, washing and forced air-drying the roof, adhesively applying a fiberglass cloth product over exposed fasteners and along lapped edge joints, and applying an asphaltic overcoat to the roof after a priming coat.
Because metal roof panels in many areas are exposed to large temperature differentials, i.e., 70.degree. F. in the state of Florida on some days, there is a considerable growth and contraction of the metal panels and the lapped edges move substantially relative to the relatively non-expansible fiberglass cloth strips covering them and tend to displace the strips. In addition to the expansion and contraction of the roof panels, wide temperature differentials create relative movement in the wood and metal structures which make up the underlying roof so that movement of the parts of the structure, in addition to the movement of the roof panels is involved. This cumulative movement frequently causes the asphaltic outer coating to pop-up, bubble, and split, and remain so damaged.
This prior art system involves removal of all debris, gravel, loose rust, and scaled previous coating, the repair of cracks, breaks, and open seams with an aluminum plastic cement, and the application of a butyl adhesive to adhere the fiberglass fabric over the joints, prior to application of an aluminum asphaltic roof coating.
Other prior art systems have utilized relatively expensive elastomeric coverings or coatings for the entire roof.